问题
I was working on geofencing in iOS. I actually want to set different regions on the map with different radius for each regions.
I actually want to know the Min and Max radius for Regions in iOS geofencing.
Thanks,
回答1:
In iOS there is no minimum radius specified. Apple says, "The specific threshold distances are determined by the hardware and the location technologies that are currently available. For example, if Wi-Fi is disabled, region monitoring is significantly less accurate. However, for testing purposes, you can assume that the minimum distance is approximately 200 meters."
(source: https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/LocationAwarenessPG/RegionMonitoring/RegionMonitoring.html#//apple_ref/doc/uid/TP40009497-CH9-SW11)
The maximum radius is specified by CLLocationManager.maximumRegionMonitoringDistance, which is specific to the device and OS. "This value may vary based on the hardware features of the device, as well as on dynamically changing resource constraints." On my iPhone 5s simulator, that value is 2128000.0 (metres, since maximumRegionMonitoringDistance is a CLLocationDistance).
(source: https://developer.apple.com/library/IOS/documentation/CoreLocation/Reference/CLLocationManager_Class/index.html#//apple_ref/occ/instp/CLLocationManager/maximumRegionMonitoringDistance and CLLocationManager.h)
In urban canyons where there are a lot of buildings (such as New York City) geofencing may not be useful regardless of distance, and you might need to rely on iBeacons.
来源：https://stackoverflow.com/questions/21374531/what-is-the-maximum-and-minimum-radius-that-can-be-set-for-regions-in-ios-geofen